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PAPEL PIEDRA/STONE PAPER

Since the late 90ies, there is a new paper called "Stone
Paper" that uses no tree-derivatives and is -allegedly- more
ecological than regular paper made from wood-pulp.

This new product was first developed by the Lung
Meng Tech Co., in Taiwan and is marketed under several trade names around the world.

I used for testing a small notebook by Miquelrius (a Catalan company) that is linked to Emana Green, a multinational company with
offices in Taiwan and New York.

The sheets of this notebook are 240 grs/m². If it were regular
wood-pulp paper, this would indicate a thickness of cardboard. But, in this
paper everything is a bit different. It feels (when pinched between one´s
fingers) as if it were a 120 grs/m² paper (at the most).

The fact that it uses "mineral powder" (calcium carbonate, a
waste material collected from limestone), is what makes it 60% heavier than
regular paper.

There are several companies producing Stone Paper and the formulations vary a lot between different
brands. But, let´s say that it is made of 70-80% of mineral powder and 30-20%
of non-toxic resin.

For instance, Fiberstone
claims to use no water, no tree-derivatives and no bleach into the
manufacturing process. Oxford uses
limestone and polypropylene. Other brands inject tree-fibers between coats of
clay, or use recycled paper mixed with the mineral powder.

The resin used to bond the mineral powder is commonly high-density
polyethylene. So, one can consider this stuff like a sort of "bio-plastic
paper."

The bad thing is that this stuff is not biodegradable. It needs to be
recycled into plastic or paper.

However, it is photodegradable. The brand Terraskin claims that their paper will begin to degrade after 6 to 9
months of exposure to humidity and direct sunlight.

Basic
properties:

It collects no static charge, is acid-free with a
neutral PH value, has
no grain, is water, grease and insect resistant, and tears with difficulty due
to a latex-like texture.
Having no grain, Stone Paper possesses
a smoother surface than traditional paper-products, obviating the need for a
coating or gloss. It burns cleanly and does not produce toxic fumes. It is
compatible with inkjet or solid-ink printers, but does
not respond well to the high temperatures generated by laser-printers.

It
folds in a similar way to regular paper, but it makes evident there is a
plastic-content into it. The matt surface will become glossy if you rub it with
the flat-surface of your nail or with a hard tool.

I did a short first test of this "Stone-Paper" by
using a regular ballpoint, a permanent marker (Staedtler
"Lumocolor") and a speedball (Pilot "G-Tec-C4,"
0.4mm point). These three
types of writing instruments perform wonderfully upon this surface. Then, I
used a regular mechanical pencil (0.7 lead). It also worked well. If you carve
some lines with your fingernail, the material gets “etched,” showing a very clear
level-differentiation. This effect is more accentuated than with regular paper.
So, the pencil and the ballpoint-tip also tend to produce some etching-effect.

Then, I tested it with fountain-pens.
First of all, one does notice a difference in "traction" (pulling
along). I mean that the friction of the tip of the nib on the surface is higher
than with natural paper. This has nothing to do with the roughness of the
surface, which is truly smooth (like that of a regular satin-finish paper). It
has to do with the nature of the bonding resin, which gives a rubber-feel to
the surface.

“EF” and “F” nibs perform better, in my
opinion, than “M,” “B” or Italics. This is because fountain-pen ink tends to
feather lots more on Stone Paper
than on a regular satin-finish wood-pulp paper. This feathering did not happen
with the speedball-ink or with the permanent-marker (fine nylon-tip), which are
alcohol-based inks. The sheet of Stone
Paper did not show any “bleedthrough”
on the reverse when using any of the mentioned inks. Zero “ghost effect,” either. Not even with a wet “BB” or with a 1.1mm
Italic. But, with these wider tips, the bigger amount of ink tends to feather a
lot and also dries a bit slower than on regular paper.

My conclusion is that, if using a
fountain-pen, Stone Paper is more
suitable for “F” nibs. But, if you write fast and apply too much pressure, you
are prone to catch a shaving of the material between the tines. So, crosstrokes
are prone to shaving and downstrokes feel smoother. This shaving is much less
likely to happen with a “B” nib, but then there is the mentioned feathering
factor. A sharp “EF” nib will tend to catch a lot on this paper. Same about a
sharp Italic for calligraphy.

I made writing tests on Stone Paper with Iroshizuku “Momiji,” Waterman “Turquoise,” Diamine “Asa Blue” and Lamy “Blue-Black.” All these inks do
feather (to a certain degree) on this paper. The feathering was always less
pronounced when using “F” nibs and more pronounced using “B” or Italic nibs.
The less feathering was achieved with the water-resistant ink Lamy “Blue-Black.”

Not a single one of these particular inks
does feather on Clairefontaine 90grs
Velouté (my favorite paper). I´m not saying there are no FP-inks out there
which won´t feather at all on Stone
Paper, but -after my tests- I conclude that most FP-inks will experience
more feathering on this paper than on most wood-pulp papers which have a satin
finish. Evidently, on a watercolor paper the feathering would be always major.

Stone Paper tends to embed the ink in a different
way to fibers of regular papers. So, there is a slight more permanence of the
traces when water is rubbed on top of the writing. But, when water remains for
a few minutes on top of the writing, it does vanish completely.

Rubbing the writing with water produces a
lot of smearing of the ink, especially on traces produced by a “B” or by an
Italic nib. But, some slight traces of the writing do stay, when on a regular
paper the trace would be a bit more intensely washed out. Of course, I am
referring now to inks which are not water-resistant. In the case of the Lamy “Blue-Black” (a water-resistant
ink), there is little difference on the effect of water-rubbing or smearing between
both papers (Clairefontaine & Stone Paper).

The water-resistance of Stone Paper is the most underlined
property by the manufacturing companies. It won´t crumble if exposed to water.
Equally it will protect the writing under the effects of water, especially when
using ballpoints, speedballs or water-resistant ink for fountain-pens. Also, it
requires more force to tear than regular paper.

Most
of the information of this article, about the manufacturing companies of Stone Paper and its composition, was
excerpted from Wikipedia and from the websites of the mentioned manufacturing companies.